Use *-gcc-ar instead of *-ar for better LTO support

BUG=15829647

Change-Id: If657464a74f5ae54e18c2520f1f19b89443ac554
Fix strtod in libc++_static for armeabi

strtod was incorrectly configured as big-endian for armeabi

BUG=16355626

Change-Id: Icd8243624dfb1407cac82c0cfdfa96f7daad04d6